So much for an al Qaeda kook’s wish to “paralyze” David Letterman’s tongue.

The feisty, gap-toothed CBS comic unleashed a 13-joke monologue last night and a Top Ten list devoted entirely to the goon who had called for his death.

“We have great audiences night in and night out, but tonight especially, it means a lot to me,” Letterman joked on his first night back from a two-week summer vacation. “Tonight, you people are more, to me, honestly, more than an audience — you’re more like a human shield.”

Other riffs on the death threat included:

* “I’m so sorry, I’m a little late coming out. Backstage I was talking to the guy from CBS. We were going through the CBS life-insurance policy to see if I was covered for jihad.”

* “You’re not going to believe what happened. A guy, a radical extremist, threatened to cut my tongue out. I wish I had a nickel for every time a guy has threatened that. I think the first time was during the Academy Awards.”

* “I have a fatwa on me. And they say the guy that issued the fatwa is an Internet jihadist. Internet jihadist! And I said, ‘Well, heck, who says Obama isn’t creating jobs?’ ”

Throughout the show, Letterman goofed on the would-be terrorist, begging guests and staffers not to declare a “fatwa” on him for bad jokes or silly screw-ups.

What was not funny was how tight security was at Letterman’s Ed Sullivan Theater on West 54th Street.

Plainclothes security officers from CBS and probably the NYPD were on hand, “for the foreseeable future,” a network source said.

“NYPD Intelligence Division did a security assessment that resulted in increased security, but we [will] not provide details of it,” Deputy Commissioner Paul Browne confirmed yesterday.

Like Browne, CBS officials were tight-lipped about particulars.

But, “[like] many other media companies, the network is known for employing a skilled and sophisticated security force,” a network source said.

Letterman, who has been the target of stalkers, extortionists and even his son’s would-be kidnapper, had angered an overseas terrorist operative with a June 8 joke about the drone strike that killed Osama bin Laden’s one-eyed successor, Ilyas Kashmiri.

“We pray to Allah to paralyze his tongue and that the righteous believers will break his neck,” a man calling himself Umar al-Basrawi, or Omar from Basra, Iraq, wrote last week on the online jihadi forum Shumoukh al-Islam.